The force telepresence telerobot system is a typical human-robot-environment-interaction system,and the telepresence is the core of teleoperation system.How to evaluate the operating performance or telepresence degree of a force telepresence teleoperation system is a basic problem.At present,the evaluation of the operating performance mainly uses the human's subjective evaluation based on the ergonomics theory.In this paper,a two-port network model of the force telepresence teleoperation system is established,and the perception and control behavior of human operator in the telerobot system is analyzed.Then we give a definition of virtual impedance as a basis for quantitatively evaluating the operational performance of the telerobot systems,which is called impedance comparative method.At last,the operating performances of existing four types of telerobot systems based on different control structures are analyzed and evaluated by using the impedance comparative method.